The present invention relates to inductive coupling and more particularly to systems and methods for positioning a device within an inductive field.
With the advent of improved and less expensive electronics, there is a growing use of wireless power supply systems. Wireless power supply systems eliminate the need for cords and therefore eliminate the unsightly mess and the need to repeatedly connect and disconnect remote devices. Many conventional wireless power supply systems rely on inductive power transfer to convey electrical power without wires. A typical inductive power transfer system includes an inductive power supply that uses a primary coil to wirelessly convey energy in the form of a varying electromagnetic field and a remote device that uses a secondary coil to convert the energy in the electromagnetic field into electrical power. To provide an inductive power transfer system with improved efficiency, it is typically desirable to provide proper alignment between the primary coil and the secondary coil. Alignment is often achieved using cradles or other similar structures. For example, the primary coil may be positioned around the outside of a cup shaped to closely receive the portion of the remote device containing the secondary coil. When the remote device is placed in the cup, the two coils become properly aligned. Although helpful in providing alignment, this approach requires deliberate placement of the remote device within the cradle. It may also limit the inductive power supply to use in connection with a single device specially configured to fit within the cup or cradle.
It is known to provide an inductive lighting system for underwater use in a pool with a magnet as set forth in U.S. Publication No. 2002/0008973 A1 to Boys et al, which was published on Jan. 24, 2002. The patent describes that the system may include a magnet for temporarily locating lamp units. Although this reference discloses the use of a magnet for locating a light in the context of an inductive coupling, the sparse disclosure relating to magnets fails to address a number of issues. First, the reference does not disclose where the magnets are located and whether or not magnets are included in both the inductive power supply and the lamp units. Second, the reference fails to show any recognition or offer any solution for the inherent tendency of typical magnets to heat in the presence of an electromagnetic field. Third, the patent fails to recognize the need for or provide any solution to address orientation of the remote device with respect to the inductive power supply.